This project will produce the first comprehensive, analytical book about physical education for girls and women in the United States during the twentieth century, based on research already conducted in nearly fifty libraries and archives around the country. The book's central figures are white and black female physical educators who taught girls and women about their bodies, exercise, and health in various settings. Gym teachers grounded their lessons about fitness and recreation in biomechanical knowledge, but also coded physical activities by gender, race, sexuality, and class. The project addresses three important questions about this unique convergence of applied science, practical instruction, and social norms. First, how did female teachers interpret scientific theories about sex and racial difference in relation to physical activity? Against the backdrop of the nature/nurture debate, the project examines why some physical educators deployed notions of anatomical and physiological difference to stigmatize the female body and restrict women's recreation and sports, while others challenged biodeterminist beliefs and inequitable opportunities. Second, what standard of femininity did physical educators embed in their scientific concepts of active womanhood? The book analyzes white and black teachers' diverse models of gender, inflected by race, class, and sexuality. It relates their ideas to the professionalization of physical education and changes in [unreadable] gender ideologies, race relations, and discourse about sexuality in twentieth-century America. Third, how did physical educators put their ideas into practice in the gym? The project develops case studies of instructional programs in public schools, colleges and universities, and white and black branches of the Young Women's Christian Association. The book fills a critical gap in scholarly literature about the history of popular health in twentieth-century America. In addition, an analysis of women's physical education will provide a historical perspective for understanding current debates about gender and health: Why do levels of physical activity in the United States vary by sex, age, and background? What are the relative benefits and risks of exercise for girls and women? How can gender equity be achieved in the gym? The book, under contract with Oxford University Press, is aimed at a diverse audience, including historians, sports medicine experts, health and athletics personnel, and general readers. [unreadable] [unreadable] [unreadable]